


Second First Time

by venDi



Category: The Umbrella Academy (Comics), The Umbrella Academy (TV)
Genre: All the Hargreeves kids are Alphas except for Five, Alpha Klaus Hargreeves, Alpha/Beta/Omega Dynamics, Alpha/Omega, And by drugged i mean he's in heat but its kind of the same thing, Biting, Bottom Number Five | The Boy, Coming In Pants, Coming Untouched, Dom/sub Undertones, Drugged Sex, Five is the peoples Omega, Incest, Klaus Hargreeves Has A Big Dick, Knotting, M/M, Mating Cycles/In Heat, Mildly Dubious Consent, Multiple Orgasms, Non-Consensual Voyeurism, Omega Number Five | The Boy, Prostate Massage, Pseudo-Incest, Rutting, Service Top, Service Top Klaus Hargreeves, Sibling Incest, Top Klaus Hargreeves, Voyeurism, pseudo-underage, this was originally a twitter thread that i reformatted to fit on ao3
Language: English
Status: Completed
Published: 2020-08-21
Updated: 2020-08-21
Packaged: 2021-03-06 18:08:53
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 4,643
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26033218
Author URL: https://archiveofourown.org/users/venDi/pseuds/venDi
Summary: Five spent his early years learning about Alpha biology -- and he knows, recognizes the sudden shift in his family's scent, that his heat has sent them all into a very,veryearly rut.
Relationships: Minor Vanya/Five, Number Five | The Boy/Klaus Hargreeves
Comments: 12
Kudos: 491





	Second First Time

**Author's Note:**

> Link to the original thread here: https://rb.gy/vjzwpa

To the shock of no one, all but two of the kids -- when they present -- are Alphas. Vanya is (thought to be) a Beta, and Five vanishes on the cusp of the kids presenting. He just missed it by a week or so.

Ben avoids it all together, being dead and all.

Later, Vanya has a very late, very medically repressed resurgence of her Alpha nature, which shocks all the Hargreeves children, but really, makes quite a bit of sense in the end.

Five though -- he got to learn what he was in the post apocalypse world, alone.

About a week and a half into his isolation, Five starts his first heat -- it's brutal, and last far longer than it should, with Five being unsure of what's happening and not having anything but his hand to help himself through it. His heats come frequently after that, always one time. 

He doesn't have the aid of repressents to stop them, and until he's older he doesn't have the mental know-how to stop them himself. Five hadn't exactly cared much about Omega biology when at home. 

He was convinced he was going to be an Alpha. By the time he's old and the commission gets him, Five has learned firstly -- how to lessen, or stop all together, his heats. 

Secondly, he's old enough by then that he simply no longer has them. It's not an issue anymore, and the commission is happy not to have to try and deal getting him hormone blockers or repressents so he can go on missions safely.

Then Five jumps back in time and lands himself trapped, forever, in the unaging body of his thirteen year old self -- days away from reliving his first heat. It's not on his mind much, at first -- he's gone on so long without worrying about them for a while now, and he's trying to stop the apocalypse. 

It's not until he's in the midst of early-stage heat that he realizes what's wrong. When it happens Five is in the house, with the rest of his siblings. He's sitting at the bar listening to them bicker about inane topics, as usual, when he gets the fourth sudden cold shiver this morning -- he worries for a moment he's caught some illness.

But that's short lived when he feels the familiar tightness in his stomach and the beginnings of dampness in his shorts as he feels the first bit of slick trickle out of him. He also notices the way that all of his siblings have suddenly stopped talking. 

Five turns around, as dawning horror strikes him, and he looks upon the room full of Alphas who stare right back at him with wide, interested eyes. They each take a long, heavy inhale as they scent the air.

They know. 

Five spent his early years learning about Alpha biology -- and he knows, recognizes the sudden shift in his family's scent, that his heat has sent them all into a very, _very_ early rut.

"Guys," Five tries, he wants to be reasonable. Smart about this. "I need to go." 

He stands and slowly, carefully, trying not to startle any of them into action, makes his way towards the door. He could blink away, solve the problem, but heats have always messed with his ability to concentrate, which messed with his powers. Safer to walk. A rattling shiver hits him and a soft moan slip from his lips as more slick trickles out. 

And that's what does it.

Utter chaos;

Luther charges full force at him, likely aiming to lift Five into his arms and try and protect him, hide him away from the others. He's shoved out of the way as Diego slams into his side with all his strength, trying to get Luther out of the way so he can get to him first. 

Allison and Vanya, with their newfound love for each other, don't fight. Instead, they come together as a united force and vault themselves over the back of the couch. Allison lands in to Five's right, Vanya to the left, and they crowd him in and try and catch him, like an animal.

Five manages to pull back from them at the last moment with a yelp, sending Allison and Vanya smacking head first into each other. They growl at each other, warning; their compassion for eachother can only go so far right now, with as far gone as they are, and an Omega so close.

Klaus is the only one Five doesn't see -- he was somewhere in a back corner, and he's likely stalking the edges, waiting for an opportunity to crawl in and take. 

Or, he was too high to notice, or drunk to get to them. Luther finally manages to shove Diego down to the ground with one of his oversized hands, barreling towards Five once again.

Five makes a mad dash for the stairs; if he can get some distance between them all, he might be able to buy himself time to think up a solution.

As he runs up the stairs, he can hear -- and see -- his siblings practically climbing over each other to get to him. Diego snaps his teeth at Allison, nearly biting her as, and Vanya ducks beneath Luther's arm and bolts up the stairs after him. 

He gets to the first landing when she catches up to him, grabbing one of his legs and pulling him back as he yelps. Vanya turns him over, crawling up until she can press her body against him, pinning him down.

"Five," She breathes, soft and caring, "You smell so good."

She scents him, sucking in a heavy breath as her fingers press insistently against Five's stomach, near his belt latch. When Five breathes in he gets a lung full of her particular scent -- Alpha, distinctly, overpoweringly so. But she also smells like snowberries, and clean linen fresh out of the dryer, soft and welcoming, comforting, but powerful. 

Five cant help but relax against her hold, instinct taking over as he moans, soft and weak. Then she is abruptly yanked off of him by Diego, and she growls and kicks at him, sending the two of them into a minor scuffle. Without her scent overpowering him Five blinks and snaps himself out of it. He still needs to get to his room before his heat gets into full swing.

He drags himself up to his knees and crawls across the floor towards the second flight of stairs -- at the top of which are their rooms. He's able to climb them mostly unbothered; Vanya and Diego's fight has stalled the others enough to grant him a few extra seconds.

He pulls himself up to his feet once he reaches the top, his knees wobbling and more slick spilling out of him. Five's face is flushed, and he feels feverish, his body trembling and waves of sweat pouring over him. His clothes are too constricting and overbearing now.

It won't be long before his heat is in full swing -- he rushes towards his room and shuts the door behind himself, locking it. It wont keep them out, any of them, not for long, but at the very least get him some time. For what, he doesn't know, but he needs to think up a plan.

Five's short moment of reprise is thrown out the window, though, as he hears someone clear their throat behind him. He whips his head around to find Klaus, standing at the far corner of his room -- he waves a tattooed hand and smiles.

"Hey."

"How did you get up here before me?!" Five demands, as he backs himself up against the door. His body is rapidly heating up, his cock hardening in his shorts and ass leaking slick at a near constant pace now.

"Went up the other flight of stairs while you guys fought." Klaus says.

Right. It was a split staircase. 

Five should have considered that. Five sucks in a heavy breath, scenting the air for himself -- trying to get a read on how far gone Klaus is. Except, he doesn't smell the familiar heavy smell of rut. Instead he smells cigarette ash and weed.

"You aren't in rut?" Five is bewildered.

"If I went into rut around every Omega in heat, Five, I'd have died from the strain by now." Klaus laughs, gesturing to the door. "They act like they've never seen an Omega in heat before."

"Probably haven't, knowing them." Five shrugs.

"Fair. How far along are yo--" Klaus is cut off by a loud banging on the door that sounds too much like Luther for comfort. 

Their time alone has ended, and now Five is frantically looking around the room for an escape. Some way to stop the hoard of horny, angry Alphas behind him.

That's when Klaus is suddenly there and grabs him by the arm, muttering a hurried 'trust me' before he tosses Five bodily onto his own bed. Five shouts as he slams painlessly into the pillow, flat on his stomach.

Klaus crawls up behind him and lays himself atop Five.

Klaus' entire body pins Five's to the bed without even really trying -- he's so tall it's quite easy for him to cover all of Five. His forearms bracket Five's head and shoulders, his stance wide as he hunches over him.

Five wants to protest, but having Klaus lay on him it feels too good, the pressure like a deep body massage, settling his stomach and relaxing him in an instant.

The door is thrown open and there stands the others, all crowded in the doorway, their eyes wild and hungry. And, upon seeing them, Klaus hunches lower and growls, low and heavy in his throat, an Alpha's growl. It's protective in it's sheer nature, and with the stance, it's clear what Klaus is trying to signal to the others --

Five is _his._

Upon hearing it Five can't help but whimper and arch his ass up into Klaus, pressing himself against Klaus' cock. It's humiliating, but god, Five can't help himself. It just feels so _right._

Of course, though, Klaus' claim to him is short lived, as Luther instantly tries to contest it. He doesn't enter the room -- with him in rut, he doesn't want to get that close when Klaus could hurt Five if he chose.

Desperate Alphas have before. Still, his answering growl is low and rattles Five's bones. Five can see it as Luther bares his teeth.

The other three growl in sync, as they too contest Klaus' bold claim. Klaus, above him, has a plan for that too, apparently.

He leans down and clamps his teeth around the base of Five's neck. Instantly Five howls and comes in his pants; Klaus doesn't bite him, but the threat is enough for his body, his instincts. 

Klaus growls once more, his teeth pressing, getting oh so close to breaking the skin, and this time his claim seems to work. The other's growls die off, and eventually they shuffle away, the door shutting as best it can with a broken lock.

Only once they have left does Klaus finally release Five's neck, unbitten, letting out a sigh.

"Sorry," He offers, apologetic. "It was the only thing I could think of on such short notice."

"'ish okay," Five slurs, his body still trembling from aftershocks. Klaus makes a squeaky noise and shifts, jerkily pulling up, between trying to get away and stay, his instincts leaving him conflicted.

"Fuck, I didn't mean to make you--" He cuts himself off, and Five watches his fingers curl into tight fists as he drools against the sheets. 

Five wants to tell him it's okay, that at this point anything will probably make him come. Instead all that comes out is a wailing moan as he cants his hips higher and grinds his ass against Klaus' now hard cock. Klaus grunts and stiffens, trying his hardest not to move.

"We shouldn't be doing this--" Klaus tries to reason, but he's leaning down closer, his forehead bumping Five's back between his shoulder blades. 

Five would normally agree -- he thinks he would have fought harder if it were one of the others. But, this is Klaus. It's different with Klaus -- it's _always_ been different with Klaus. 

They'd gravitated towards each other as children, one of the few people Five could tolerate around him, touching him, _teasing_ him. And Five _hasn’t_ touched him much at all since he's been back -- hasn't touched anyone, really. 

Hasn't touched people much since he was still actually thirteen, the night before he left, as Klaus made some stupid joke under the stars and Five had had no choice but to kiss him on the cheek. 

Five aches with the need for comfort, for contact, for Klaus to just hold him and make him feel better -- memories of his first heat, alone and scared, are overwhelming, and he hates them. Wants to feel safe and okay for once in his life during a heat. Like you're supposed to. 

"We shouldn't," Five agrees with a whine, rocking back against Klaus. "But would you if I asked?"

There's a heavy pause as Klaus mulls it over, before; "Are you asking?"

"Yes."

"Then yes."

As soon as permission is granted Klaus surges forwards and buries his head in the crook of Five's neck and inhales, deep and heavy; Five does the same, getting a feel for Klaus' scent. 

While he's not in rut, he's still reacting to Five's heat, hormones acting in overdrive and making him put off a scent that is, biologically, engineered to make Five feel better. Or, really... any Omega.

Klaus' general, heavy Alpha scent is muted in comparison to the others -- it's there, for sure, but even despite it being less from him not being in rut it's still even less than normal. He's not an overbearing Alpha, his hormones not as strong, instincts muddled. 

Probably a contributing factor in him being able to resist going into rut, as well. Klaus _also_ smells like fresh rain, and coffee grounds, campfire smoke and the slick scent of gun oil. 

Where Vanya's scent had been almost entirely her own, less tailored for Five specifically, something her body had stamped as markedly hers Klaus' is made almost entirely for Five. 

His body targeting Five far more accurately than Vanya's likely ever could -- her own individual smell likely too ingrained in her personality to change much.

The smell has Five moaning and reaching up, grabbing Klaus' hair. 

"You smell sweet," Klaus hums, his hand snaking beneath Five to press against the still-prominent tent in his shorts. The contact makes Five whine, his underwear and shorts stained and damp from his own come.

"Like sugar. Roses and chocolate."

They say what an Alpha smells on an Omega is telling; telling how the Alpha sees them, as the Omega's body caters to them. Something about how Klaus smells him makes sense to Five. Makes sense because that's something that Klaus would get, something Five knows he would like. 

Klaus rubs his clothed cock and presses a kiss to Five's neck, and he comes again with a strung out whine; the first heat Five had gone through he'd come so many time he'd lost count. Surrounded by Alphas he knows his heat is going to be stronger even than that. 

Klaus retracts his hands only to pull at the neck of Five's suit jacket. "Let's get this off, yeah, Fives baby?" He asks, using one hand to help Five up into a kneeling position. "Get you more comfortable."

"Yeah," Is all Five can manage to say, trembling still. Klaus strips him with care, gently removing his jacket, tie, vest, and shirt; once they're removed he rubs his thumbs over Five's hard nipples. 

He presses kisses to Five's neck, lines himself up so when Five arches backwards Klaus' cock slips between his cheeks. Five babbles nonsense as Klaus strokes over his chest, going up from his hips with pressure, his big hands splayed around Five's chest with ease. When he gets back up to Five's chest Klaus sucks a dark mark onto his shoulder.

And Five comes again with a sob; he'd been telling the truth when he'd said that anything was going to get him to come right now. When he'd been in the future and had his first heat, Five had come from a gust of wind hitting his naked cock. 

Klaus makes a low rumbling noise that sounds like a purr, his hand -- god his hands are so big on Five's body -- slips down to the front of his shorts and into them, into his underwear. He palms cock and makes another noise.

"So wet." Klaus giggles. He moves his hand across Five and Five can hear the obscene, wet noise of it, even muffled beneath two layers of clothing. 

Five can't help himself as he shakes and moans, clutching Klaus' hair far too tight for comfort. He feels another wave of come squeeze out from him, sliding down Klaus' knuckles and back into his already soaked shorts. 

Five's body shivers violently as he feels slick slide down his legs, over his thighs -- when he presses back against Klaus' legs he can feel as he rubs it off on his jeans.

"Ah," Five moans, screwing his eyes shut. "Oh, fuck, fuck, Klaus, please--"

"I know baby, I know," Klaus murmurs into his ear, retracting his hand from his shorts. He makes quick work of his belt, the zipper, before hooking his thumb in the waistband and pulling his shorts and underwear down in one tug. 

Klaus manhandles Five, lifting him up into the air as if he weighed nothing and sliding his underwear and shorts past his knees and down. Five is left in nothing but his socks, which Klaus pointedly leaves on. 

"Five," Klaus laughs, and he dips his fingers inside Five's hole, a loud slick noise echoing in the room as Five squeals and throws his head back, rocking down against those fingers instantly. 

"You're so fucking wet. I've never seen an Omega this soaked so fast."

"Maybe it's cause your body is so young and your mind isn't? It can't handle all those hormones?" Klaus pumps his fingers in and out of him, fitting two, three, even so far as slipping in a fourth.

"Or maybe it's the house full of raging, horny Alphas in rut."

Five doesn't know -- and really, at this point, he doesn't care. All he can think about is the hard line of Klaus' cock that's still trapped behind his jeans, and the oh-so _good_ drag of his fingers inside him.

Five makes a choked off noise as he comes again, his hand flying down to press against his cock. Not to jerk himself off, but instinctively, unknowing what else to do against the onslaught of pleasure that hits him. His come shoots out and stains the sheets as he claws at his own thighs, jerking against Klaus violently. 

"Aw," Klaus says, voice soft. "You need it that bad, little Five?"

"P-Please," Five sobs.

"Alright, I can do that, let me help." Klaus offers, and puts his hand against Five's shoulder. 

Instantly Five keens and falls down face first into the mattress. He pushes his forehead into the sheets and presents his neck, offering, _begging._

A rattling growl from Klaus in response has Five arching harder, his hips raising for Klaus, to give Klaus better access. Klaus hand wraps around the back of his neck and squeezes. 

"You're gonna make it hard for me not to bite you," Klaus pants, his nails digging into skin.

"Yes," Five hisses, rocking back against the fingers still inside him. "Please, oh fuck, please, Klaus, bite me--"

"Shit, shit." Klaus shakes above him with the strain. Klaus shifts closer, leaning down, he's so close he could bite Five if he wants to but -- when nothing happens Five turns his head and looks behind himself. 

Klaus has bitten his own forearm,his teeth sinking in deep enough he spills blood. Five whines, worry managing to cut through the haze of lust for a moment. Klaus though doesn't seem worried, and he lets himself go and sits back up, smiling.

"I can't bite you, silly," He says, pulling his fingers out finally. "Not until your heat is over and we've talked about it."

"Because _I_ don't want right-mind Five to kill me for biting out-of-his-mind-with-heat Five."

Five knows, somewhere, in his mind, that Klaus is right; still though he whines and pouts, pushing back against the hold Klaus has against him to try and instigate something. He stops struggling when he hears Klaus unlatching his belt and his zipper pulled down, Five moaning obscenely. 

Klaus takes no time getting his cock pressed against Five's hole -- somewhere in the back of Five's mind he does notice, though, that Klaus has a condom on. He'll thank him for it later, not risking infections or -- anything else.

"Ready?" Klaus asks, and Five wails and claws at the sheets, trying to push himself back against his cock. He's too far gone now for coherent speech, but Klaus laughs, getting the message.

"I'll take that as a yes," He says, before _finally_ pushing into Five's body. His cock is long, and thick -- not overly so, but enough for his small body to still ache despite all the slick that's easing the way. 

Five makes a series of aborted noises as he scrambles nowhere, writhing, trying to get away from the sudden _perfect_ press of pleasure inside him. He comes once more, wrung from him with each inch Klaus pushes forwards.

_"Ah,_ ah, hah," Five moans, feeling come hit his stomach. Klaus sinks fully into him with a satisfied moan, one of his hands pressing on the small of Five's back until his chest is flat against the bed. 

His other holds open Five's cheeks so he can get a good view of himself pushing into him. Klaus starts up a pace that is by no means enough, but Five takes what he can get right now, his body trembling and too weak to push back against Klaus any longer. He can do nothing but lay there moaning as he takes it. 

Five's vision is blurred and he can feel the heavy press of Klaus' knot bump into him with each thrust. He knows from what he'd read that his head will end faster if Klaus knots him -- biology a bitch, making him content only when he's stuffed and full. 

Five knows his heat will last a long time -- the first time it'd happened it had been four days straight of hell, where he was spending every waking moment stuffing himself with his fingers or the nearest dick-shaped object he could find. He would prefer not to spend four days on his back once more. If he can get this to stop today he's going to.

_"Khh,"_ Five babbles, trying to articulate Klaus' name. He can't quite manage it. "Haah, _ple--_ please."

"What do you need, Fives?" Klaus rumbles, ever the doting Alpha. He noses along the back of Five's neck, pressing kisses there, but not biting him.

Five rocks back against Klaus hard, almost managing to get his knot to breach him. Klaus squeaks and jerks, holding Five still. 

"I don't think that's smart--" Klaus starts, but Five ignores him with another moan and thrust back against him. Klaus hisses and his hips stutter.

"Five, Five, baby, I can't know you want this, fuck," He digs his fingernails into the flesh of Five's shoulders. 

"Please," Five moans.

It's apparently enough for Klaus; "If you get mad at me for this I will cry. I'm very sensitive post knot."

That's all the warning Five gets before Klaus rocks forwards and his knot pushes past the ring of muscle, an obscene popping noise accompanying it.

Five screams and pulls the fitted sheet up from the corners, biting his own forearm as the sudden pressure is _too good, too much, too fast, not enough._

It's like someone is pressing right against his prostate as hard as they can without letting up. He comes again -- his entire body shaking so hard his teeth rattle in his skull, his eyes rolling up into the back of his head as he makes a strained, high noise. It's like being hit by a bus or a train, and Five can't stop as come shoots out of him, his body convulsing. 

He's not sure when it happens, but he whites out, mind blanking and consciousness drifting from himself for a moment. When he manages to come back to Klaus is laying almost all his weight on him. 

The haze of foggy lust and confusion, desperation, seems to have left him finally his thoughts clear for the first time today. When he shifts, he can feel the way his stomach bulges around Klaus' cock and his come, feels the way the condom has filled on his load.

Thank god for ultra strength latex. 

Five puts a hand to his stomach and feels the definite shape there, the literal bulge in his gut, the shape of Klaus' cock and knot too much for his small body. 

Five's own cock gives a futile twitch and he bites his lip, whining, his body trying to get him to come again. Thankfully he doesn't, body wrung dry finally.

"Hey," Klaus huffs above him, no doubt noticing Five shifting around. "Welcome back, how was the trip." 

Five grunts -- his emotions are swirling in his chest like lead weights, too many thoughts hitting at once. With all those hormones flooding his system, he can't help but ache for some kind of comfort, now. 

A stupid aspect of being an Omega that Five had always loathed -- still, for the first time, he can do something about it.

He reaches out and takes Klaus' hand in his own fitting their fingers together. Klaus makes a soft noise and presses a kiss to the back of his head.

"Someone's feeling sappy." He teases, and Five flushes, screwing his mouth up.

"Shut up," He bites out, voice hoarse. "I'll kill you."

"Later, I'm sleepy." Klaus wraps his hands around Five's stomach and carefully pulls them to the side until they lay, spooning, still joined, on the bed.

Five huffs a breath but allows it -- and he freezes when he hears a heavy boot fall outside the door. There's the sound of hushed voices and more footfall, retreating, and Five's brows pinch together.

"Was that--"

"They sat outside the door," Klaus confirms, his laugh making Five's hair jostle. "Now that you've been knotted they're heat-induced ruts are probably ending."

Five's face screws up, "Disgusting voyeurs. I hate Alphas."

"But you love me?" Klaus whines, pressing kisses to Five's cheek.

"Sure, whatever," Five's face burns and he slaps Klaus away -- still, his other hand remains joined with Klaus'. 

"I knew you weren't all heartless bastard in there," Klaus says, too happy for his own good. "I don't wanna be them tomorrow when they have to face your wrath."

Five grunts. "No. You do not want to be."

Five is already planning the death of them; disemboweling for Luther, castration for Diego, beheading for Allison, and a special knife-meet and greet for Vanya for dragging him across the floor by the ankle. 

Klaus pulls him from his thoughts by wrapping an arm around him, pressing a series of kisses to Five's shoulder and his cheek once more. Five grunts, annoyed, but doesn't fight it. He'll never admit it, but it's comforting to be held like this, after so long alone. 

They stay like that -- wrapped together and holding hands, Klaus occasionally pressing kisses to Five's face or body -- until the morning when the scent of coffee wakes Five up.

  
He gives a very, _very_ stern talking to the rest of them. 


End file.
